Tapping clamp for high voltage electric live lines



June 6, 1933. FREEBURY 1,912,519

TAPPING CLAMP FOR HIGH VOLTAGE ELECTRIC LIVE LINES Filed June 12, 1930 l aten'ted inn-e 6, i933 UNITE STATES PATENT OFFICE PAUL EREEBUEY, OF OAMAR-U, NEW ZEALAND Application filed June 12, 15-30, Serial No. 4. 60581, and in New Zealand February 14, 1839.

This invention relates to electric live line tapping clamps, and more particularly to tapping clamps adapted for use in connection with high electric voltages.

The object of the invention is to provide an electric cable tapping clamp or connector by means of which high voltage transmission lines can be tapped and secondary electric cables connected thereto while said high voltage lines are alive thereby obviating the necessity of di' erting the current from the same.

According to the invention the clamp comprises a hook-shaped body member carrying a hinged pallet, the free end of which can e given movement towards or away from the hooked end of the body member by means of set screw working through the said body member.

This set screw a.,. apted to be turned to raise the pallet and clamp the electric cable between the latter and the inner face of the hooked end of the body member, by means of an 7 tool mounted on one end of a n0nconducting handle of suitable length, said affixing tool comprising an end spanner containing a T bolt-head slot milled in from one side of a round bar.

The set screw works in an internally screwthreaded cylindrical boss formed integral with the body portion, and said cylindrical boss near its lower end is partially cut through in a transverse direction and completely cut through in its longitudinal direction from said transverse cut to its lower end. The portion so out is given a slight inward set so as to form an internally screwed spring portion adapted to act on the set screw and act on the latter in the manner of a lock nut.

A hole drilled through the back of the body member provides means whereby a cable thimble. having attached the secondary or tapping cable, can be bolted to the device prior to its being ElfilXOCl to the main or live line, and a stop cast on the body member at the side of this thimble provides means for preventing turning of the latter and consequent loosening of its retaining bolt.

The invention will, however, be more particularly described with reference to the accompanying drawing, wherein Figure l is a perspective view of the device having a secondary or tapping cable connected to it, in process of being aflixed'to a main electric line (dotted) by means of an atlixing tool, thetop end only of the latter being shown.

Figure 2 is a side elevation of the device with one side of the pallet broken away.

Figure 3 is a plan view thereof, and,

Figure l is a sectional plan view thereof on the line AA., Figure 2, while Figure 5 is a plan view of the top end of the affixing tool.

The clamping device consists of three main parts, namely, a body member 1 having a hook shaped upper end 2 and a cylindrical boss 3 having its axis coinciding with the vertical centre line through the apex of the angle formed by the head of the hooked portion 2: a pallet or pivoted arm 4- hingcd to said body member 1: and a set screw 5 acting on the free end of the pallet 4 and working through an internal screw thread in the boss 3.

The body member 1 comprises in its main portion a flat rib carrying at its upper end a downwardly turned hook portion 2 of T section, its inside. faces being plane surfaced at anangle of 90 degrees and of sufficient area to carry the required current without heating. The vertical rib of the T section of the hooked portion 2 is provided by an extension of the body member 1, and the horizontal flanges forming the remaining ribs of said section are cast integral therewith.

The body member 1 carries the hinged pallet l near its upper end, said pallet 4 being located so that its tree or movable end may be given movement in an approximately vertical plane towards and away from the apex of the inner face of the hooked portion 2, by means of the set screw 5, to clamp the live wire or cable 6 between itself and the angle of the inner face of the hooked portion 2. The lip of the hook 2 is slightly tapered and projects downward at an angle of degrees to the vertical to enable the device to be readily hooked over the live wire 6.

The portion of the body member 1 carried over the hook 2 to form the vertical rib thereon gives strength to the said hook without unduly increasing its weight.

The lower end of the body member 1 provides a landing for a cable thimble 7 in which h as been previously secured the tapping wire 8. A hole 9 is provided in the body member 1 for the purpose of securing the thimble 7 to the device by means of a bolt 10 and nut 11, and a thickened portion 12 is cast on the side of the body member 1 to provide a stop adapted to prevent turning and consequent loosening of the thimble 7 and its nut 11, and also to prevent the said thimble 7 and wire 8 from turning down and fouling the afiixing tool during the operation of clamping the device on the live wire 6.

At one side of the lower portion of the body member 1 is formed a cylindrical boss 3 internally screw threaded to receive the set screw 5, and disposed so that its axis lies ina vertical plane and is directed to the apex of the inner face of the hook 2. The lower extremity of the boss 3 contains a horizontal cut 13 extending approximately half way through said boss, and a vertical cut 14 through the outerside of the boss extending from the horizontal cut 13 to the lower end of the boss 3, thus forming a pair of wings in the sides of the latter which can be slightly set inwards to produce a spring action on the set screw 5 and prevent turning of the latter accidentally.

The sides of the body member 1 at a point a little below the angle of the hook 2 are increased in thickness to form a landing for the arms of the pallet 4 so that the width of the hinged pallet and the inner face of the hook 2 may be approximately the same. The hole through this thickened portion of the bod-y member 1 through which the hinge rivet 1A of the pallet 1 passes is sufficiently larger than the rivet 4A to permit a certain amount of float so that the said pallet under pressure of the set screw 5 may adjust itself against the wire 6 without undue straining of the pallet arms.

This thickened part of the body member 1 is also shaped on the front so that the pallet may swing down clear when the set screw 5 is fully withdrawn, to permit easy application to or removal from the wire 6 of the device as may be required.

The hinged pallet 1 is a casting of cylindrical shape having extending from its ends at right angles two flat arms which pass on either side of the thickened portion of the body member 1 and are hinged to the latter by means of the pivot pin 4A. The cylindrical portion of the pallet 4 can be either a complete cylinder, or may be grooved or angular to oppose the angle in the hook 2 as desired.

The afiixing tool 15 consists of an end spanner having a T-bolt slot 16 milled in one side of a round bar (as shown in Figures 1 and 5). The tool 15 is then secured on one end of a treated wooden or other insulating handle 17 of suitable length.

The afiixing tool 15 being slipped over the head 5A of the set screw 5, the clamp with its tapping wire 8 attached, is raised by means of the handle 16 and the clamping device is hooked down over the live wire 6 which lodges neatly in the angle of the hook 2. The affixing tool 15 is then, with a slight downward pull exerted upon it, rotated by means of its handle 17 to tighten up the set screw 5, thereby raising the pallet 4 and clamping the wire 6 between the latter and the angle of the hook 2.

To remove a clamp already upon a wire 6, the affixing tool is slipped over the head 5A of the set screw 5, a little downward pressure is exerted, and the said tool rotated to loosen the set screw 5, there by permitting the pallet 1 to fall clear of the wire 6, and the clamp can then be lifted off the said wire by means of the affixing tool.

Vv hat I claim as new and. desire to secure by Letters Patent is 1. A high voltage live line clamping device comprising a cylindrical body member formed with a longitudinally ranging threaded bore. a hook-shaped portion carried by and overlying the body member and presenting a relatively broad inverted V -sh= ped section overlying and spaced from the cylindrical body member, the apex of the V-shaped section being in vertical alignment with the center of the threaded bore and the free end of the overlapping portion of said section extending below the top edge of the cylindrical body member and spaced therefrom to form an open mouth adapted to receive a wire, a seat formed at the juncture of the cylindrical body member and one leg of the V-shaped section, a pallet comprising a pair of arms with aligned openings, and a cross bar connecting the arms, said cross bar extending across the center of the cross bar and the apex of the V-shaped section when in wire gripping position, a pin extending through the openings in the arms and an opening in the V-shaped section to form a pivotal connection, an d a screw operating in the threaded bore, the upper end of the screw adapted to engage the cross bar when tilted on its pivot to grip a wire in the apex of the V-shaped section, the cross bar fitting in the seat to free the mouth of obstruction for introducing a. wire when the screw is in its lowermost position.

2. A high voltage live line clamping device comprising a cylindrical body member formed with a longitudinally ranging threaded bore, a hook-shaped portion carried by and overlying the body member and presenting a relatively broad inverted V-shaped section overlying and spaced from the cylindrical body member, the apex of the V-shaped section being in vertical alignment with the center of the threaded bore and the free end of the overlapping portion of said section extending below the top edge of the cylindrical body member and spaced therefrom to form an open mouth adapted to receive a wire, a seat formed at the juncture of the cylindrical body member and one leg of the \/-shaped section, a pallet comprising a pair of arms with aligned openings and a cross bar connecting the arms, said cross bar eX- tending across the center of the cross bar and the apex of the V-shaped section when in wire gripping position, a pin extending through the openings in the arms and an opening in the V-shaped section to form a pivotal connection, the opening in the V-shaped section being of larger diameter than the pin connecting the arms to provide a slight floating action of the pallet when clamping a wire, and a screw operating in the threaded bore, the upper end of the screw adapted to engage the cross bar when tilted on its pivot to grip a wire in the apex of the V-shaped section, the cross bar fitting in the seat to free the mouth of obstruction for introducing a wire when the screw is in its lowermost position.

3. A high voltage live wire clamping device comprising' a. cylindrical body member formed with a threaded bore, a V-shaped port-ion extending from the cylindrical body member, a pallet comprising a pair of arms connected by a cross bar and mounted on the if-shaped portion to have a slight floating action, a seat formed at the upper edge of the cylindrical body member, a screw mounted in the threaded bore, the free end of the screw engaging the cross bar when gripping a wire, the cross bar engaging in the seat when the screw is withdrawn in the bore to afford an uninterrupted passage for the introduction of a wire to the V-shaped portion, and friction means on the cylindrical body member to engage the screw to assist in holding said screw in set position when a wire is clamped.

In witness whereof I have hereunto set my signature this 2nd day of May, 1930.

PAUL FREEBURY. 

